Method of utilizing floating soap and derivatives thereof



Patented Mar. 5, 1935 UNITED STATES PATENT OFFICE I Paul Hodges, Tuscaloosa, Ala., assignor to Gulf States Paper Corporation, a corporation of Delaware No Drawing.

12 Claims.

My invention relates to what is known in the paper industry as floating soap, that saponaceous product which is formed in the black liquor used for digestion in the production, of paper or other cellulosic products by the sulphate or the soda process, and which in part separates and floats as a scum to the top of the liquor drained from the pulp after digestion, and which also is in part in solution in the liquor and further quantities may be separated out by centrifugal separation or other methods.

A particular object of my invention is to provide an improved emulsifying and suspension agent which is particularly useful in suspending or dispersing water immiscible substances generally and in the separation of minerals by flotation. 1 l

A further object of my invention is to provide improved stable emulsions of oil, waxes, and related substances and suspensions of fine solid particles in water, oil or other liquids.

Floating soap, so called, contains the. alkali salts of a complexity of fatty and resinous acids, higher alcohols, and a number of other compounds, many of which have not. as yet been identified. While no dependable analysis of floating soap? is available, it is known to treat the product, for example, as set forth in the U. S. Patent to Michelson, No. 1,823,752, in such a manner as to free the acid constituents and alcohols from the floating soap and obtain a complex mixture of such constituents which is known in the trade as Tallol.

Among'the compounds which have been identified in floating soap are the sodium salts of oleic acid, palmitic acid, linolenic acid, capric acid, and linoleic acid, and unidentified unsaponifiable compounds. (Hasselstrom Paper Trade Journal, July 8, 1926, page 60; Chem. Abs. 20: 3566). Also in Sandquist, Berichte 64 B, page 2172-4; (Chem.

Abs. 26: 472) there are identified a salt of lignoceric acid, lignoceryl alcohol and phytosterol. Aschan in Finska Kem. Medd. 1918, page 8 (Chem. Abs. 13: 2868) describes salts of pinabietic acid. Dittmer in Z. Angew. Chem., vol. 39,- page 262 (1926) (Chem. Abs. 20: 2072) describes abietic acid as well as confirming the work of other investigators, and mentions other unidentified hydrocarbons. i

E. Phyala in Svensk. Pappers Tid. vol. 29, 601-4, 627-9 (1926): (Chem. Abs. vol. 21, page 2072) separates the so-called "floating soap according to viscosity into twelve classifications ranging from easily mobile fatty oil to a black asphalt like resin. Among compounds not mention d y the Application January 9, 1938, Serial No. 650,862

investigators and identified by this author are ricinoleic acid, erucic acid, erythrose and mannose.

Besides the above mentioned compounds, the so-called soap contains free sodium hydroxide, free sodium'sulphide, free sodium carbonate, free sodium acetate, and other unidentified materials. The physical and chemical properties of difierent samples vary to a certain extent depending upon the conditions of manufacture, and the 10 woody material from which it is obtained.

Floating soap is soluble in hot water, alcohol, petroleum hydrocarbons, and, to a certain extent, in practically all organic solvents. The oils and resins precipitated by the neutralization of the soap with the acids apparently form a homogeneous mixture.

Emulsz'fying agent oil of lavender, stearic acid, dichlormethane, linseed oil, and turpentine.

The general procedure in producing an emulsionwith floating soap is to melt or mix the material to be emulsified with the soap, and. then add water, with agitation. After a thoroughly homogeneous emulsion is obtained, the mixture may be further diluted. In the case of some materials, such as linseed oil, it is to advantage to add a small amount of fatty acid-to produce a more permanent emulsion. This appears to have the eiiect of lowering the pHvalue and raising the hydrogen ion concentration, and thus making emulsification of the material easier.

" In the case of linseed oil, the following example will-give a water-in-oil type of emulsion, which is very stable: Melt together floating soap (30% moisture) 5 parts, oleic acid 1 part, linseed oil 5 25 parts. When thoroughly mixed add slowly, with agitation, 25 parts of water. This emulsion may be diluted with water to very low concentrations.

, ,In making emulsion of paraflin wax, I may use soap 10 parts, wax 10 parts, oleic acid 3 parts, and melt together. parts of water are then added, with violent agitation.

In making rubber emulsions, ammonia or ammonium hydroxide is added to the soap in the place of oleic acid, as it is of advantage to raise the pH value and raising the hydrogen ion con-.- centration. In this case, the proportions of the materials are not particularly important. I have successfully emulsified pine oil, rosin, casein, mineral oil, ethylene dichloride, oil of lavender, stearic acid, and dichlormethane, by melting with the floating soapancl then adding water without the use of oleic acid. However, in some cases this oleic acid would have made a smoother emulsion.

The emulsions thus formed are unusually stable and possess relatively high dilution ratios. Ihe floating soap being of relatively low cost renders the material especially attractive for use as an emulsifying agent.

Pigment suspension agents I have further discovered that "floating soap is particularly useful in the production of suspensions of pigments orother fine solid particles in water, oil or other liquids. For example, suspensions of such materials as china clay, titanium dioxide, titanox B, and red lead may readily be made.

In using the soap" to produce suspension of pigments or other fine solid particles in water, oil, or other liquid, the soap is dissolved in the liquid until a clear solution or an even emulsion is obtained, and then the pigment is added, with violent agitation.

For example, if a 5% solution of floating soap is made in water 10%, to 15% of the weight of the solution in pigment such as titanium dioxide, may be stirred in, and will remain in suspension for a considerable length of time. Of course, the time necessary to settle out depends upon the fineness and nature of the pigment. Other things being equal, a solution of floating soap will suspend, or defiocculate, pigments for a much longer time than water or gum arabic and glue solutions such as have heretofore been used,

Among the particular advantages of floating soap as a suspension agent are its high solubility in water, oil and other common liquids, and its low cost.

Collection and jrothing agent in flotation processes I have discovered that floating soap is an especially effective collection and frothing agent in flotation processes, particularly in the flotation of sulphide or oxide minerals. It is also effective in the separation of fibre from white water, graphite from its associated materials, and in the separation of numerous other materials.

In carrying out flotation by this method, a 1% to 2% solution of floating soap is mixed with the mineral to be floated, so that not too thick a slurry is obtained. A flne stream of air or violent agitation produces a froth. As the froth apparently floats and collects both the oxide and sulphide minerals, it seems to have'the'advantages of xanthate and soap flotation at the same time. The froth may be easily broken down and the floating mineral recovered by means of the alcohols, acids or acid fumes. It also has the advantage of extremely low cost, making recovery unnecessary.

While I have shown my invention'in several forms, it will be obvious to those-skilled in the art that it is not so limited, but "is susceptible of various other changes and modifications, without departing from the spirit thereof, and Idesire, therefore, that only such limitations shall-be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims. I

What I claim is:

1. An emulsifying and suspension agent comprising floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material.

2. An emulsifying agent for emulsifying paraffin wax, pine oil, rosin, casein, rubber, foam oil, lubricating ofl, ethylene dichloride, oil of lavender, stearic acid, dichlormethane, linseed oil, and like water immiscible organic compounds, comprising floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material.

3. A suspension agent for pigments and other finely divided solid substances in water, oil, and other liquids, comprising floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material.

4. A method of making emulsions of oils, waxes, resins, pitches, gums, and other liquids and solids not otherwise miscible with water, which comprises mixing the material to be emulsified with floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material, and adding water with agitation.

5. A method of making emulsions of oils, waxes, resins, pitches, gums, and other liquids and solids not,otherwise miscible with water, which comprises mixing the material to be emulsified with floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material, adding a fatty acid, and then adding water with agitation.

6. A water emulsion comprising floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material, and a substance selected from the following: oils, waxes, resins, pitches, gums and other liquids and solids not otherwise miscible with I water.

7. A water emulsion comprising floating soap" obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material, and a substanceselected from the following f'T'OilS, waxes, resins, pitches, gums and other liquids and solids not otherwise miscible with water, and a fatty acid.

8. An emulsion comprising substantially ten parts each of floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material, paraffin wax, substantially three parts of oleic acid, and fifty parts of water. I

9. An emulsion comprising substantially five parts floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material, linseed oil twenty-five parts, oleic acid one part, and water twenty-five parts. i

10. A method of making a suspension of fine particles of solid matter which comprises providing a solution of floating soap" obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic-material in water and stirring in ten to fifteen per cent of the weight of the solution of the substance to be suspended.

11. A method of making a suspension of fine particles of solid matter in a liquid which comprises mixing floating soap obtained as a floating scum from the black liquors in the manufacture of sulphate or soda cellulosic material with the liquid to obtain a clear solution or an even emulsion and adding the fine solid matter with violent agitation.

12. A suspension agent for use in a flotation process comprising floating soap" vobtained as a floating scum from the black liquors in the manufacture of. sulphate or'soda cellulosic material.

PAUL HODGES. 

